Switch construction



11 1946 w.o. SCHULTZ Em 2,401,910

SWITCH CONSTRUCTION Filed June 23, 1944 4 Sheets-Sheet 1 INV Mum/u 0. JCl/Ul 72 June 11, 1946 w, 0, SCHULTZ ETAL 2,401,970

SWITCH CONSTRUCTION Arr 4w: v.

J1me 1946. w. o. SCHULTZ ETAL SWITCH CONSTRUCTION Filed June 25, 1944 4 Sheets-Sheet 3 IN V EN TORS Mun-1M 0. Ja/uzrz Ana/1v 6. Jim/Mame ATTOk/VEV.

w. o. SCHULTZ ET AL 2,401,970

June 11, 1946.

' SWITCH CONSTRUGTION Filed June 25-, 1944 4 Sheets-Sheet 4 INVENTORS Mum/u 0. Jam-r2 BY flaw 0. Jim/mm? Patented June 11, 1946 SWITCH CONSTRUCTION William O. Schultz, South Milwaukee, and Alwin G. Steinmayer, Milwaukee, Wis., assignors to Line Material Company, Milwaukee, Wis, a

corporation of Delaware Application June 23, 1944, Serial No. 541,730

14 Claims. 1

This invention relates to a switch construction and is particularly directed to a high voltage switch uch as a disconnecting switch for instance, although the invention is not limited to this type of switch.

Objects of this invention are to provide a construction which is applicable either to a single switch Or to a gang type switch, in which a multiplicity of switch blades or switch members are provided and are adapted for simultaneous actuation.

Further objects are to provide a switch construction in which the parts are carried by insulator stacks, and in which the construction is such that the insulator stacks are not strained by stresses tending to draw them together or force them apart, in which the switch arm may be as long as desired and may be constructed of tubular stock, whereby it weight may be reduced, or, if desired, may be constructed from rod or other stock material, in which a high contact pressure is secured between the stationary contact means and the movable contact means when the switch is c1osed, in which this high pressure is relieved prior to opening of the switch, and in which the component parts of the arcing horns are kept out of contact when the switch is closed, thereby lessening the chance of the arcing horns freezing tight under sleet conditions, and in which a certain portion of the arcing horn construction is moved into contact with the remaining portion of the arcing horn construction during opening motion of the switch.

Further objects are to provide a switch having a pivoted switch arm construction provided with resilient switch arms and with mechanism which not only secures high contact pressure between the movable and stationary contacts but also is so made that it secures high contact pressure at the pivoted portions of the switch, thus avoiding the necessity of using a flexible leader and insuring high contact pressure at both ends of the switch.

Further objects are to provide a switch construction in which cylindrical switch members preferably of tubular form are employed, in which a high contact pressure on a stationary contact is obtained at opposed points on the stationary contact so that the pressure are balanced, thus eliminating external stresses, and to provide a construction in which the cylindrical main switch members grip between them a cylindrical stationary member, thus obtaining a small area high pressure contact, the movable contacts extending transversely across the stationary contact when the switch is closed.

Further objects are to provide a switch construction which is so made that no latches are required to insure correct sequence of operation of the parts but instead in which simpl mechanisms are provided, and in which the construction i such that the inherent resiliency of the switch arms is utilized.

Further object are to provide a construction in which the switch arm portion is so made that it is laterally braced, in which the parts cooperate to insure correct centering or positioning of the movable contacts when the switch arm is rocked to closed position and to provide a construction which is very simple, which is highly reliable in operation, and which is economical to manufacture.

Thi invention is an improvement over that disclosed in the copending application of Alwin G. Steinmayer, Serial No. 501,233, filed September 1943, for Switch constructions, and further objects of thi invention are to provide a switch construction having the characteristics enumerated hereinabove which is so made that the switch may be mounted in any desired position-horizontally, Vertically, or even in an inverted positionwith the assurance that the different mechanisms will function in their correct sequence irrespective of the position in which the switch is mounted.

In greater detail, further objects of this invention are to provide a switch construction in which a pair of resilient switch arms are employed and are spread apart by means including toggle link mechanism so as to cause their outer ends to grip a stationary contact between them when the switch is closed, the arrangement being such as to insure a straight line locking toggle action for the toggle link mechanism during the major portion of the closing stroke of the switch with the provisions of an adjustable tripping means for breaking the toggle at the time the movable contacts are about to engage the stationary contacts, further motion of the parts producing a powerful gripping action of the movable contacts on the stationary contacts.

An embodiment of the invention is shown in the accompanying drawings, in which:

Figure 1 is a side elevation, partly broken away, showing the switch construction in closed position.

Figure 2 is a plan view of the structure shown in Figure 1 showing the switch in closed position with heavy contact pressure applied.

Figure 3 is a view corresponding to Figure 2 showin the switch in closed position with the heavy contact pressure relieved.

Figure 4 is an enlarged sectional View adjacent the pivot end of the switch arms with one of the switch arms sectioned off.

Figure 5 is a line section taken on the line 55 of Figure 4.

Figure 6 is a sectional view on the line 6--B of Figure 4.

Figure 7 is a sectional view on the line 1-1 of Figure 2.

Figure 8 is a sectional view on the line 8-8 of Figure 1.

Figure 9 is a diagrammatic view very much exaggerated showing the lines of flexure of the switch arms.

Figure 10 is a sectional view showing a gang switch, such section corresponding to a section on the line I-I 0 of Figure 1.

Referring to the drawings, it will be seen that the switch comprises a base I which supports three stacks of insulators indicated by the reference characters 2, 3 and 4 The insulator stacks 3 and 4 are stationary whereas the stack 2 is revolubly mounted and is rigid with a vertical shaft 5.

The stationary contact comprises a stationary terminal 6 in the form of a cylindrical pin having a tapered upper portion and integrally formed with a base portion I from which a connecting tongue or terminal 8 projects. The stationary terminal or contact 6 is provided with a stop pin 9 which projects from opposite sides thereof and against which the outer end portions of the movable arms are adapted to rest When the switch is closed. This stop pin may be formed as a separate member rigid with the contact pin 6 or may be formed integral with the contact pin 6. A pair of arcing horns II] extend upwardly from the base I of the stationary terminal, as shown most clearly in Figures 1 and 8.

The switch comprises a pair of spaced tubular switch arms II which are provided with inner portions I2 pivotally carried by a transverse shaft or pivot Din I3 which in turn is supported by a pair of pivot supporting members I4 carried by the insulator stack 3. A pair of stops I5 are also supported from the insulator stack 3 and are mounted rearwardly of the portion I2 of the arms II and are adapted to engage such arms and limit the opening motion thereof when the arms II have been rocked about the pin I3 through slightly more than 90 to the dotted line position shown in Figure 4.

The arms II are preferably of tubular construction and may be formed of any metal having good electrical conductivity and having some degree of resiliency for a purpose hereinafter to appear. A pair of fittings I6 are rigidly secured to an intermediate portion of the arms II and slidably carry the ends of a pivot pin H, see Figure 5. The pivot pin pivotally supports a rocking arm I 8, see Figures 4 and 5, which arm is provided with a downwardly extending cam portion I9 provided with cam faces 20 on opposite sides thereof and terminating in lower, outwardly projecting'stop portions 2| and outwardly projecting upper stop portions 22.

The cam member I9 constitutes deflecting means for deflecting the intermediate portion of the arms in a manner hereinafter to appear. A second pair of fittings indicated by the reference characater 23 is also attached to the arms II, see Figures 2. 3 and 7. These fittings 23 are pivotally joined by means of the pin 24 and thus piv-.

otally connect the arms II adjacent their outer ends but at a point spaced inwardly from the outer ends. The fittings 23 carry the movable arcing horn members or wipers 25 which engage the stationary arcing horns I0 when the switch is being opened or being closed.

The means for rocking the arm I8 and cam member I9 comprises a member pivotally mounted on the pivot pin I3 and provided with a pair of arms 26. The arms 26 are joined to the arm I8 by means of a pair of links 21, pivot pins 28 and 29 being carried by the arms 26 and I8, respectively. A spring 30 is loosely looped about the pin 28 and urges the links 21 towards clockwise motion about the pin 28. The rocking or pivoted member having the arms 26 is operated by means of a connecting rod 3I, see Figure 2. This connecting rod has its forward end formed in the manner of a yoke like portion which carries a vertical pivot member 32 by means of which a connecting member 33 is pivotally joined about a vertical axis to the connecting rod 3I. The connecting member 33 is pivoted on the pin 28 and thus provides a universal joint between the rocking arms 26 and the connecting rod 3 I. The other end of the connecting rod is similarly provided with a connecting member 34 pivoted on the pin 35 carried by the connecting rod 3| and pivoted on the crank pin 36 carried by the crank arm 31, which latter is rigid with the revolubly mounted insulator stack 2. It is to be noted that the pivot member 35 and the crank pin 36 are at right angles to each other and thus constitute a universal joint connection. The pivot supports IE are preferably formed integral or rigid with' a conducting strap or member 38 which extends outwardly and provides the second terminal portion for the switch.

It is preferable to provide a central pin 31' which is integral with the crank 31. This central pin is revolubly mounted in the rigid conducting member 38 and thus serves to mechanically tie the upper ends of the insulator stacks 2 and 3 together and prevents any stresses tending to separate such stacks or to draw such stacks towards each other from being imposed on the stacks.

When the switch is in its fully closed condition, the parts occupy the position shown in Figures 1, 2, 4 and 6. The cam member I9 is in its lowermost position and the intermediate part of the tubular arms I I engaged by the cam are deflected or pressed outwardly so as to cause the arms to take the approximate shape shown in an exaggerated manner in Figure 9. The cam member I9 exerts forces indicated at F in Figure 9 against intermediate portions of the arms II and inasmuch as the arms are resilient, causes the arms to bow outwardly at their intermediate part. The inner end portions I2 bear against the pivot supporting means or ears I4, see Figure 2, and are held in binding engagement therewith when the switch is closed. The arms II pivot about the pin 24 and cause their free outer ends to bind against and tightly grip the stationary contact or pin 6. The binding engagement at the pivoted and outer ends of the arms is relieved prior to opening the switch.

-A small area high pressure contact is thus obtained between the movable contacts or arms II and the pin 6. It is to be noted also that the movable arcing horns 25 move inwardly from their dotted line position shown in Figure 9 out of contact with the stationary arcing horns I0 and thus freezing together of the stationary and c movable arcing horns during sleet conditions is prevented.

When the crank 31 is rotated in a clockwise direction, the initial portion of its rotating motion is translated into a rocking motion of the cam member I9 so that the cam member I9, see Figure 4, is rocked upwardly in a counterclockwise direction, thus allowing the intermediate portion of the arms I I to move inwardly and to release the heavy tight grip of the outer end portions of the arms II on the stationary pin or contact 6 and also to relieve the heavy pressure between the inner ends I2 of the arms and the pivot supports I4, see Figure 3.

When the arms H are relaxed, the movable arcing horns engage the stationary arcing horns II], as shown in Figure 3. Continued rotation of the crank 3'! draws the links 2! and the arms I8 towards a straight line position. Complete straight line position at this instant, however, is prevented as the arm [8 engages an adjustable stop 39 carried by a stop support 40, see Figure 4. However, the pull of the links 2! on the arm I8 raises the switch arms II and the switch arms rock upwardly to the dotted. line position shown in Figure 4 slightly past 90 and the inner end portions I2 of the arms II engage the stationary stops I5 and arrest the motion of the composite movable switch arm.

The links 27 and the arm I8 then occupy a straight line position as shown in the upper dotted view in Figure 4. The links 21 and the arm I8 thus constitute a toggle link mechanism and thus act as means for positively locking the cam member or deflecting the member I9 against mo tion with reference to the arms II. The links 21 and the arm l8 are urged towards their straight line position by means of the spring which additionally insures the attaining of the straight line position or looking position of the links 21 and the arm l8. If desired the links 21 and the arm I8 may pass slightly beyond their straight line position.

When it is desired to close the switch, the crank 31 is rotated in a counterclockwise direction as viewed in Figure 2 and this causes the rocking arms or levers 26, the links 21 and the arm I8 and the switch arms I I to rock as a rigid structure, pivoting about the pivot pin I3. There is no need for catches or other fasteners to insure the correct sequence of operations for there is no chance of motion of the cam member I9 due to the locking of the toggle link mechanism 21, I8 hereinabove described.

As the movable switch arms I I continue downwardly towards their contact engaging position or closed position, the toggle link consisting of the links 21 and the arm I8 retains its straight line position until just at the time the arms II are about to engage the contact 6. The stop 39, see Figure 4, engages the arm I8 and starts collapse of the toggle link mechanism, thereby not only causing a thrust motion to be imparted to the arm I8 through the pin 29 but also causing a slight rotary motion of the arm I8 and cam member I9. However, the force required to spread the arms is sufficient to temporarily retard further rotation of the cam member I9 about the pivot pin II until the switch arms II actually engage the stop pin or stop means 9, see Figure 1. It will be seen, therefore, that the adjustable member 39 constitutes a trip means for tripping the locking means, which latter temporarily locked the deflecting means against motion relative to the arms I I. When the outer end portions of the arms I! engage the stop pin 9, see Figure 1, the thrust on the arm IB is then effective to rotate the cam member I9 about the pin I1 and thus give the spreading or deflecting action to the intermediate portion of the switch arms to cause tight gripping between the outer end portions of the arms II and the stationary contact 6.

It is to be noted that the stop 39 is adjustably held to the support 40 by means of a screw 4| located in a slot formed in the sup ort 40 or in any other suitable manner so as to allow for any necessary final adjustment to insure breaking of the toggle at the desired point in the switch operation.

It is apparent that the switch can be mounted in a horizontal position as shown in the drawings or can be mounted in a vertical or even an inverted position as desired. If the switch is mounted in an inverted position and the switch is being closed, it is apparent that the pressure exerted laterally by the arms I I due to their resiliency against the cam member I9 will prevent the cam member from passing upwardly between the arms and expanding the intermediate parts of the arms prior to engagement of the outer ends of the arms with the stop pin or member 9 and the switch will, therefore, function equally well in an inverted, vertical or horizontal position as required.

The switch is usually in the form of a gang switch in which a plurality of switch units are employed as shown in Figure 10. The shafts 5 are provided with rock arms 42 which are rigid therewith and are connected by means of a series of connecting links 43. One of the rock arms is connected by means of the connecting link 44 with a crank 45 mounted on a control shaft 46. The crank 45 is adapted to be rocked through at least so as to lock the switches in both open and closed position.

If desired, the crank 45 could rock slightly past dead center at each end of its stroke to insure locking.

It is to be understood that the switch arms II may be made as long as desired depending upon the voltage of the circuit in which the switches are to be used.

It is to be noted further that the switch arms II are not mounted one above the other as has often been done in prior practice but are mounted opposite each other in the same plane. This provides a laterally braced movable structure.

It is to be noted also that no jumpers or flexible conductors are required between the stationary portion of the switch and the pivoted arms II at the inner ends of the arms II as the inner portions of the arms II, when the switch is in fully closed position, are in firm binding engagement with the stationary conducting portion of the switch.

It will be seen further that there is no chance for the successive operations of the switch parts to occur in an improper sequence although no latch or other temporary holding means is provided but that the structure is such as to inherently insure a correct sequence of operations of the parts.

It is to be noted that the force causing the binding engagement at the outer and inner ends of the arms is transmitted directly to the arms from the deflecting member and no auxiliary parts are required for transmitting the forces to the inner and outer ends of the arms. Thus an extremely simple construction is provided and one having a relatively small number of parts.

It will be seen that the arms are held against longitudinal motion with respect to each other. At their rear ends the pivot pin prevents longitudinal shifting of either arm with respect to the other and at the outer ends of the arms the fittings 23, see Figure 2, prevent relative longitudinal shifting of either arm with respect to the other. The fittings 23 constitute tie members and prevent lateral separation of the immediately adjacent portion of the arms where the fittings are located. It will be seen from this construetion, therefore, that the arms together with the tie members and the pivot member constitute a braced structure and thus the switch is relatively safe against undesirable lateral swaying or shifting, The rocking arms, therefore, are accurately guided during the closing motion of the switch into their correct position, the outwardly flaring arcing horns also assisting in this operation as well as the tapered or pointed upper end of the stationary contact 6 for the final positioning of the outer ends of the arms.

It is to be further noted that the arms are resilient and that the intermediate portions of the arms are deflected outwardly and the outer portions of the arms are deflected in the reverse direction, that is to say, are forced to assume a reverse curve from that of the intermediate portions when the switch is closed and the heavy contact pressure applied.

Although this invention has been described in considerable detail, it is to be understood that such description is intended as illustrative rather than limiting, as the invention may be variously embodied and is to be interpreted as claimed.

We claim:

1. A switch construction comprising a pair of spaced arms, means pivotally supporting the rear ends of said said arms, a stationary contact adapted to be engaged by said arms adjacent their outer ends, means joining said arms at a point spaced inwardly of the outer ends of said arms, deflecting means for deflecting an intermediate portion of said arms to cause said arms to bind against said stationary contact, operat ing means for moving said deflecting means and rocking said arms towards and from said stationary contact, and mechanism for insuring operation of said deflecting means only when said arms are in proximity to said stationary contact.

2. A switch construction comprising a pair of spaced arms, means pivotally supporting the rear ends of said arms, a stationary contact adapted to be engaged by said arms adjacent their outer ends, means joining said arms at a point spaced inwardly of the outer ends of said arms, defiect ing means for deflecting an intermediate portion of said arms to cause said arms to bind against said stationary contact, operating means for moving said deflecting means and rocking said arms towards and from said stationary contact, and locking means for positively locking said deflecting means against motion with respect to said arms when said arms are rocked away from said stationary contact.

3. A switch construction comprising a pair of spaced arms, means pivotally supporting the rear ends of said arms, a stationary contact adapted to be engaged by said arms adjacent their outer ends, means joining said arms at a point spaced inwardly of the outer ends of said arms, deflecting means for deflecting an intermediate portion 01' said arms to cause said arms to bind against said stationary contact, operating means for moving said deflecting means and rocking said arms towards and from said stationary contact, locking means for positively locking said deflecting means against motion with respect to said arms when said arms are rocked away from said stationary contact, and means independent of said locking means for releasing said locking means when said arms are rocked into proximity to said stationary contact.

4. A switch construction comprising a pair 01 spaced arms, means pivotally supporting the rear ends of said arms, a stationary contact adapted to be engaged by said arms adjacent their outer ends, means joining said arms at a point spaced inwardly of the outer ends of said arms, deflecting means for deflecting an intermediate portion of said arms to cause said arms to bind against said stationary contact, operating means for moving said deflecting means and rocking said arms towards and from said stationary contact, locking means for positively locking said deflecting means against motion with respect to said arms when said arms are rocked away from said stationary contact, and adjustable means independent of said locking means for releasing said looking means when said arms are rocked into proximity to said stationary contact.

5. A switch construction comprising a pair of spaced arms having inner pivotally supported ends and having outer spaced ends, a stationary contact adapted to be engaged at opposed points by the outer spaced ends of said arms, means pivotally joining said arms at a point spaced inwardly of their outer ends, deflecting means for deflecting an intermediate portion of said arms to cause relative motion of their outer ends to engage said stationary contact at spaced points, operating means for rocking said arms towards and from said stationary contact, and toggle link mechanism for operating said deflecting means.

6. A switch construction comprising a pair of spaced arms having inner pivotally supported ends and having outer spaced ends, a stationary contact adapted to be engaged at opposed points by the outer spaced ends of said arms, means pivotally joining said arms at a point spaced inwardly of their outer ends, deflecting means for deflecting an intermediate portion of said arms to cause relative motion of their outer ends to engage said stationary contact at spaced points, operating means for rocking said arms towards and from said stationary contact, toggle link mechanism for operating said deflecting means, and spring means biasing said toggle link mechanism towards straight line position.

7. A switch construction comprising a pair of spaced arms having inner pivotally supported ends and having outer spaced ends, a stationary contact adapted to be engaged at opposed points by the outer spaced ends of said arms, means pivotally joining said arms at a point spaced inwardly of their outer ends, deflecting means for deflecting an intermediate portion of said arms to cause relative motion of their outer ends to engage said stationary contact at spaced points, operating means for rocking said arms towards and from said stationary contact, toggle link mechanism for operating said deflecting means, spring means biasing said toggle link mechanism towards straight line position, and means for breaking said toggle link mechanism when the outer ends of said arms are in proximity to said stationary contact.

8. A switch construction comprising a pair of spaced arms having inner pivotally supported ends and having outer spaced ends, a stationary contact adapted to be engaged at opposed points by the outer spaced ends of said arms, means joining said arms at a point spaced inwardly from their outer ends, a cam arranged to coact with said arms to deflect an intermediate part of said arms to cause the outer ends of said arms to engage said stationary contact at spaced points, and means including locking toggle link mechanism for rocking said arms towards and from said stationary contact and for selectively locking said cam and for moving said cam.

9. A switch construction comprising a pair of spaced switch arms having inner pivotally supported ends and having outer spaced ends, a stationary contact adapted to be gripped between the outer spaced ends of said switch arms, tie means connecting said switch arms together at a point spaced inwardly from the outer ends of said switch arm, pivot support means adjacent the inner ends of said switch arms, a cam adapted to be forced between an intermediate portion of said switch arms to deflect said intermediate portion to thereby cause binding between the inner ends of said arms and said pivot support means and to cause the outer ends of said switch arms to grip said stationary contact, said cam being pivotally carried by said switch arms and having an arm projecting outwardly, operating means for raising and lowering said switch arms and rocking said cam, and a link connecting said operating means and the arm of said cam and coacting with the arm of said cam to form a locking toggle link mechanism to lock said cam in retracted position when said switch is open.

10. A switch construction comprisin a pair of spaced switch arms having inner pivotally supported ends and having outer spaced ends, a stationary contact adapted to be gripped between th outer spaced ends of said switch arms, tie means connecting said switch arms together at a point spaced inwardly from the outer ends of said switch arms, pivot support means adjacent the inner ends of said switch arms, a cam adapted to be forced between an intermediate portion of said switch arms to deflect said intermediate portion to thereby cause binding between the inner ends of said arms and said pivot support means and to cause the outer ends of said switch arms to grip said stationary contact, said cam being pivotally carried by said switch arms and having an arm projecting outwardly, operating means for raising and lowering said switch arms and rocking said cam, a link connecting said operating means and the arm of said cam and coacting with the arm of said cam to form a looking toggle link mechanism to lock said cam in retracted position when said switch is open, and stop means arranged to break said locking toggle mechanism when said switch is nearing completion of its closing motion.

11. A switch construction comprising a pair of spaced switch arms having inner pivotally supported ends and having outer spaced ends, a stationary contact adapted to be gripped between the outer spaced ends of said switch arms, tie means connecting said switch arms together at a point spaced inwardly from the outer ends of said switch arms, pivot support means adjacent the inner ends of said switch arms, a cam adapted to be forced between an intermediate portion of said switch arms to deflect said intermediate portion to thereby cause binding between th inner ends of said arms and said pivot support means and to cause the outer ends of said switch arms to grip said stationary contact, said cam being pivotally carried by said switch arms and having an arm projecting outwardly, operating means for raising and lowering said switch arms and rocking said cam, and a link connecting said operating means and the arm of said cam and coacting with the arm of said cam to form a locking toggle link mechanism to lock said cam in retracted position when said switch is open, each of said switch arms when in open position being substantially straight and when in closed position being reversely curved on opposite sides of said tie means.

12. A switch construction comprising a pair of spaced arms, pivot means for the inner ends of said arms, pivot support means on opposite sides of said arms, a stationary contact adapted to be gripped by the outer ends of said arms, and mechanism for moving said arms to open and closed position and for forcing the inner ends of said arms apart into binding engagement with said pivot support means and for forcing the outer ends of said arms towards each other to grip said stationary contact, said mechanism including deflecting mechanism for moving said arms laterally and locking toggle link mechanism for locking said deflecting means when said arms are in switch open position.

13. A switch comprising a pair of spaced arms having inner pivotally supported ends and having outer spaced portions, a stationary contact adapted to be en aged at opposite points by the outer spaced portions of said arms, means pivotally joining said arms, deflecting means for defleeting a portion of said arms spaced inwardly from said last mentioned means to cause relative motion of their outer ends to engage said stationary contact at spaced points, operating means for rocking said arms towards and from said stationary contact, toggle link mechanism.

for operating said deflecting means, said toggle link mechanism being arranged to look when said switch is in open position, and means for breaking said toggle link mechanism when the outer ends of said arms are in proximity to said stationary contact.

14. A switch comprising a pair of spaced arms having inner pivotally supported ends and having outer spaced portions, a stationary contact adapted to be engaged at opposite points by the outer spaced portions of said arms, means pivotally joining said arms, deflecting means for deflecting a portion of said arms spaced from said last mentioned means to cause relative motion of their outer ends to engage said stationary contact at spaced points, operating means for rocking said arms towards and from said stationary contact, toggle link mechanism for operating said deflecting means, said toggle link mechanism being arranged to look when said switch is in open position, and means for breaking said toggle link mechanism when the outer ends of said arms are in proximity to said stationary contact.

WILLIAM O. SCHULTZ. ALWIN G. STEINMAYER. 

